Talking-machine record and method and apparatus therefor



'n. HIGHAM. TALKING MACHlNE RECORD AND METHOD AND APPARATUS THEREFOR.

APPLICATION FILED JUNEjH. 1920- v Patented Apr. 25, 192 2.

rukA-zzO-m I D. HIGHAM.

1,414, 1 s5, Patented Apr. 25, 1922.

mnm 11mm m.

MUDDY Mummy 5 IR TrIITr n'H 4 ATTORNEYS I new and useful Improvements in Talking- DANIEL BIG-HAM, or nas'r O ANGE, NEW JERSEY.

' 15 TALKING-MACHINE nnconn AND METHOD AND APPARATUS mnemon- To all whom it may concern:

Be it known that I; DANIEL HIGHAM, a citizen OjjheUnited States of America, residing at, East Orange, in the countyof Es-. sex and State of New Jersey, have invented Machine-Recordsand Methods and Apparatus Therefor, of which the'following is a specification. 7 This. invention relates to recording of sound waves for a talking machine record, and its -object is to so provide for this recordingthat the distortions ordinarily made in recording and reproducing sound waves 15' can'be correctly compensated for.-

With present recording means and methods, the amplitude of the recorded sound wave is reduced in amount by the opposing action of the recorder diaphragm,fand the lower the pitch with relatively greater amplitude of the sound wave, the greater the ratio of this reduction of amplitude of the recorded sound waves willbe, compared to.

the original sound waves.

With talking machine reproducers now in use, the fulcrumal resistance for the transmissionof'the recorded sound wave yibration' to the diaphragm of the reproducer is inertia only-of the reproducer as a body;

, to offset each other to axvery great extent,

in-.;ifact a 'simplesustained sound wave may be recorded throughout several octaves and reproduced in the exact relative amplitudes of the original by this bayancing-up of the present recorder for the present reproduc'er; but for compound vibrations. such as produced by a string or hammer-blow ty e of musical instrument, the fundamental Wlll Joe,

the only vibration to follow such balance, for the reason that therecorderdiaphragm acts to reduce the amplitude of an overtone vibration precisely as much as it does Application filed. June 11,

made by the re- Speciflcation of Letters Patent. Pafentd Apr; 1922.

1920. sem nemesis.

' 1 when wthfll} vibration is a fundamental,-

whereasthe re roducer will relatively increase the amp itude of that vibration only when it is the fundamental orlowest Vibration taking place at that instant.

Furthermore, the firsthalf wave start of a continued'sound'wave vibration is always reduced in amplitude andreduced in length by both present recorder and present prof ducer, while the continuation is alwaysad?- vanced in phase; In other words, there is always a discrep'ancy'in. present \fbalancing up of the recorder and reproducer, becausethe are not a complete inverse of each other.

ow I propose to compensate for the dis- 'tortions of the present reproducer byg recording a complete inverse of the reproducer distortions for the talking machine record. This I accomplish by making the recorder means actuate a reproducer means at the I means, and by making that means movable time of recording through an amplifying v a vibration of the same will be setup m;

portional to the amount of inertia of that body, whereby the recording stylus lever can be 'fulcrumally supported"'by that inertia-resisted body, and the vibrations of the same will act to distort'the soundvwav'e vibrations transmitted-from the recorder or soundreceiving diaphragm to the exact inverse of the distortions made by the present talking machine. y Or more specifically,, by my -method of balancing up the recorder and reproducer distortions, the first half wave of asound wave vibration of given pitch will be recorded with an exaggerated increase of amplitude and length while the continuation of that wave will be recorded with reduced amplitude and lagged in phase; whereby thepresent reproducer, acting to reduce the amplitude of the first half wave and decreasing its length and acting to increase the amplitude and advance the phase of a continued recorded sound -wave, will' distort to reproduce the exact original sound .wave- I.

character.

,Inorder 'to makemy invention clearly unders'tood, reference will be made tothe accompanying drawings,- of which Flg. 1 is a side elevation, partly in section, of means for carrying my method oftoe recording into effect;

Fig. 2 is a view, partly in section, looking I from the left of Fig. 1 with certain parts removed from the left ofthe dash line V; Fig. 3 shows a portion partly in section, Fig. 4 a part .in another view; Fig. 5 is a diagram showing a different position of parts of Fig. 1; while Fig. 6 graphically shows the performance I of my method of recording as distinguished from present recording, and the distinguishing performance of each when operating the present reproducer.

In the means shown, 1 is a usual recorder diaphragm, but held at its extreme periphery by a soft rubber ring 2 having a V- shaped groove moulded in its inner circumference and adjustably clamped in a casing 3 by a cap 4 with screws 5. The extended end of the casing 3- is for connection with a suitable recording horn and .is adjustably clamped in a support 6 bya cap 7 and screws 8. The casing 9' is provided with a sound reproducing diaphragm 10, held between rubber gaskets 11 by a ring cap 12fixed in position by a wax fillet 13.. The extended end of the-casing9 is for connection with a suitable reproducing horn, and is adjustably clamped ina support 14 by a cap 15 and screws 16.

A friction rotor 17 and a friction band or cord 18 constitute means for amplifying the power of the .sound vibrations. Passing through an pening 19 in cap 4 is a connecting piece 20 aving a small finger 21, shown in Fig. 4, which passes through dlaphragm v 1 and is waxed therewith. This piece 20 has a small hole 22 in which a loop spring 23 engages, and two fingers 24 between which the friction cord 18 with a knot 25 engages. In like manner, the flattened end of a round connecting piece 26 engages with the opposite end of the friction cord 18 and between center pointed screws 32 (Fig, 2),

and carries a usual sapphire recording point 33 which passes through its lower end and is secured by shellac in proper position. A

cord 34 (Fig.1) also passes through this lower portion of the lever 28 and is fixed thereto by a'knot in said cord and is likewise secured in the hooked .end of a spring'35. :having'connection with an adjustable frame portion 36 provided with a pivoted screw 37 set in a center spot of a support 38.

The friction rotor 17 of the amplifying means is fixed to a shaft 39 (Fig. 2) between 1 a shoulder 40 thereon and a screw 41, as

shown in Fig. 3, a groove 42 being employed to guide the friction band 18. swinging bearing hanger 43 for the shaft 39 is freely pivoted to a support 44 by a pin 45, and the. opposite end of the shaft 39 is provided with a ball-shaped bearing in a support 46 having a suit-able cap 47 and screw 48. A pulley 49, fixed to shaft 39 by a pin 50, is 1'0- tated in the direction of the arrow 51 (Fig.

ed screws 32 which support the recording lever 28. The frame 56 also carries center pointed screws 57, which seats in center spots in a support 58. The recording blank 53 is supported, centered at its bore 60, rotated about its axis 61 in the direction of arrows 62, and advanced so that the axis 61 travels directly towards the recording sapphire 33, to scribe the usual spiral recording groove, all by usual means,

he recording blank 53 may be shaved true in the same supporting means by suitable rotating means, with the usual sapphire shaving knife supported as near the recording sapphire 33 as possible. The .desired depth of recording groove is made by adjustment of the frame of the recording means relatively to the recording blank, by usual means. The friction rotor 17 may be of any suitable metal, (preferably not easily corroded) if the friction band or cord 18 has been soaked in a thin solution of glue and water, and dried. This serves to effect a proper coefficient of friction, providing about the average or proper degree of humidity is maintained in the recording room. Or the friction rotor 17 may preferably be made of, amber, say inside the dotted lines on each side of the guiding groove 42 shown in Fig. 3, while the portions outside the dotted lines may be of metal to=effect the necessary amount of inertia resistance of that swlnglng body, or it may be further increased if need be by a suitable inertia col-' lar 63, which may be fixed to the shaft 39 byfla set screw 64. With the amber rotor, humidity is not important, and the increase of the power (not the amplitude) of the sound vibration transmitted from diaphragm lto the recording lever 28 and reemphasized with small circles indicatepivoted points upon a fixed support, while the lines connecting the different points indicate the parts designated by same-figures of reference in..Fig. 1. From this it will be seen thatif the friction rotor 17 were action ofthe spring 35 in Fig. 1 will be nil in exerting pressure upon either diaphragm 1 or diaphragm 10 when the rotor 17 is in motion. I

. The proper operation'of the means shown and described is .brought about inthe following manner: The screws 5 are carefully adjusted to compress the rubber ring 2 sufficiently to just compress the circumference of diaphragm 1 to the critical point of mak; ing a flip-flop action for the same, but at the same time absolutely without that action. This adjustment makes diaphragm '1 slack in the middle and destroys all elastic diaphragm action, required for present recording, within the limit of amplitude permitted by the recording space. ,The cap 4: with its suitable opening 19, determined by experiment, offers air resistance 'to the sound vibrations of diaphragm 1, andcompe'lsthe vibrations of the same to be undistorted in character from the original sound waves. That is, the resistance offered by air in this manner tends to lag the phase of the vibrations of diaphragm 1, but this same resistance being also against the air vibration of the source, causes dissipation of the air vibration in front of the recording horn which tends to advancethe phase of the vibrations of diaphragm 1, therefore both actions result onlyin reduction of amplitude Without distortion of character from the original sound wave. The distortive action of the reproduc'er diaphragm 10, however, is essential for the correct; performance of this method of recording, but the-same must not be imposed against diaphragm 1. This is accomplished by the friction amplifying means in giving the necessary, vibrating power to the movements of diaphragm 10 my method of recording from the but only resisting the vibrations of diaphragm' 1' by 1/60 of that amount. In this way vibrations of diaphragm 1 will only be slightly opposed; but owing to the. full force of the amplifying means acting to vibrate the diaphragm 10 of the reproducer element, and the swlnging support 43 offering no fulcrumal res1stance for the transmission of the sound vibrations from the friction means to diaphragm 10, excepting inertia of the. swinging parts, the resultant wave vibrations of the swinging parts are compelled to be transmitted to 'the fulcrumal support of the recording lever 28, whereby the correct sound vibrations transmitted to the upper end of therecording lever 28 will combine with the said fulcrumal vibrations to effect resultant vibra-' tions of the, sapphire recording point 33- producer, in order that the present repro-' ducer will distort to the sound character.

In order to more fully'bring tinguishing characteristics method of recordin and the present recording method, and t eir distinguishin performances in reproducing, I shall ma e ref erence to the graphic performances depicted exact original out the disbetween my in Fig. 6. These performances are lettered a, b, a, 03, e, 7", g, k and 2', and each ne is plotted so that the same oint' of time is carried from one to the ot er by "the same ordinate line, while the equal spaces of the ordinate lines indicate equal duration of time. The straight line in each plotting indicates the normal position of vibrating parts, while the length of the small ordinate lines in each plotting indicates the amount of amplitude at that particular instant. The

plot a is a simple sine wave which willbe assumed to be the original sound wave characterwith its inception at the first ordinate line to the left. Plot b is the approximate sound wave character which will be recorded by existing recorders from the original wave character a.

Plot cis the character of sound wave which will be recorded in accordance. with sound wave character a.

' A comparison of the distorted recorded.

sound wave 12, dueto elastic resistance of the recorder diaphragm, and the invertedly distorted wave 0 recorded by my method of,

recording, will clearly show the marked distinction of the latter by the greatly increased amplitude and length of the first half wave as compared to the greatly wave of the former.

sine wave, which is due tothe elastic diare-' duced amplitudeand length of the first half Itwillalso be seen a that the wave shown by plot bis not a true original use phragm resistance of the present recorder being greatest at the tip and trough of the wave.

Plot (1 shows'by the line of dots-the undistorted wave Qfdiaphragm 1 of my means of recording, and shows by the line of dashes the wave effected by the inertia resisted swinging parts of the amplifying means,

which actions both combine to record the wave character shown in the full line, or to record. the wave shown in plot 0. Plot 6 shows by the full'line the wave shown in plotv b as recorded by known methods, and

shows by the line of dashes the wave effected I by the inertia-resisted fulcrumal body of thepresent reproducer, while the lengths of the small ordinate linesindicate the amount of the reproduced amplitude. From this it will be seen that the first half wave is greatly sacrificed while the whole wave action is advanced in phase relatively to the original sound wave a.

Plot f shows by full line the wave effected by my method of recording shown in plot a and shows in dashes thewave effected by-the inertia-resisted fulcrumal body of the present reproduger. that the length of the corresponding Ismail ordinates are precisely the same as with the original sound wave character shown in plot a. The wave effected by the inertia-resisted fulcrumal body of the reproducerordinarily used is not only-"lagged one-quarter wave In plot g I have shown a puff character of sound impulses, which may be representative of the fundamental character of a voice note, of a comet note, or the note of any windtypd if musical instrument, and which will be assumed tobe the original character ofthe pufi' impulses. The direction of the puffs above the normal line: will be assumed to be towards the ear, and will be referred to area positiveimpulse.

I Plot it shows by full linethe distortion from the original impulse effected by recorder at pres'entuse and the line of dashes indicates the wave" effected by e'rtia-resisted f ulcrumal body reproducer, while the lengths'of the small ordinates indicate the amount of amplitude.

the inreproduced. From this it will be seen that while the original plot 9 shows onlypositive Froin this it will be seen of the present impulses, the plot h shows both positive and negative impulses constituting the same pitch, but effecting exaggerated" loudness with great distortion of character.

Plot z' shows by the full line the sound impulses shown in the original plot 9 as distorted in accordance with my method of recording by the inertia-resisted swinging parts of the amplifying means acting as in-' dicated by. the dotted line, while the dash line shows the wave effected by the inertia.

resisted fulcrumal body of the present reproducer. From this it will be seen that the ultra positive action effected by my method of recording shown by the full line above the normal line, will be exactly compensated for by the action of the reproducer in effecting an equal negative action below the dash line, whereby the actual reproduced impulse character will be precisely'the same as the original character depictedin plot 9, as indicated by the'small ordinate line in each of the g and i plots.

With some makes of talking machine "records the first half wave action shown in plot e is recorded, so that the reproducer at present in use effects a negative action for same in order to make the first prominent half wave effect the positive action; but with my method of recording the positive 1 action of the original must be recorded to be reproduced as a positive action.

It Wlll be lmpracticable to enter into a dis-- cussion of complex sound waves in this disclosure, but it should be clearly understood, if the first half wave of a simple sound wave can be reproduced relatively ,to the continuation of the same that any complexity of sound wave vibrations within the range of record ability can be reproduced in their.

exact relative. values by a record produced by my method of recording. With present recording, however, the more complex the sound vibrations the more continuously will the first half wave distortive action be taking place, and the more concerted the sound vibrations, such as produced by orchestra or band, the more difficult will it be to distinguish a stringed instrument from a brass instrument; but with my method of recordmg the sound of each instrument will at all .times be reproduced with the characteristics of each instrument.

With present recording the elastic action of the recorder diaphragm being non-dissipative, that is acting to give back the energy stored up in its elasticresistance, often levelops into an explosive vibration known in the art as a blast, whichmay vibrate be 0nd the limit of the recording space.

ith my method of recording, however, this is impossible, for the, reason that the elastic diaphragm action is not only destroyed, but the recorder diaphragm is also subjected to thedissipative action of air resistance; while the blast tendency of the present reproducer is completely overcome by recording with a reproducing element acting 1nvertedly, namely, instead of the blast action resulting in a vibration beyond the recording space it will tend to bring the same to zero amplitude, as indicated by the action illustrated in Fig. 5.

Manifestly, any talking machine record, to exactly compensate for distortions of the present talking machine reproducer, must be recorded with those distortions exactly inverted in accordance with my herein disclosures.

The amplifying means shown and described inthis application are old in the art of amplifying sound vibration and I'desire it to be understood that myinvention may be used in connection with other amplifying means. v t 1 v I claim as my 1nvention:

1. A method for recording a talking ma-- ing a talking machine record, said method consisting of distorting through the action of suitable amplifying means the recorded sound waves by inertia-resisted vibrations inversely to the distortions effected by inertia-resisted fulcrumal vibrationsof the reproducer, for the purpose described.

3. A talking machine record having the recorded sound waves with distortions inverted to the distortions efl'ected in amplitude and phase by the talking machine reproducer.-

L. A talking machine recording apparatus provided With suitable amplifyingmeans in combination with inertia-resisted vibrating means acting to record a complete inverse of the distortions normally produced by a talking machine reproducer.

5. A talking machine recording apparatus comprising a recording element, a reproduc- 1ng element, and suitable amplifying means in combination with inertia-resisted vibrating means whereby the distortions of the reproducer element will be transmitted inversely to the recording element.

In testimony whereof I have signed my name tothis specification.

DANIEL HIGHAM. 

